No LED-based lighting fixture uses a voltage regulator and a series resistor to limit the current through the LED.

The LED is driven by a current regulator; yes, it usually has a small sense resistor to measure and adjust the driving current, but that's something totally different from a resistor used to limit the current.

Remember, the 'D' in LED stands for (semiconductor) "Diode", which means that in forward conduction it has an exponential relationship between current and voltage. The only way to control the brightness is to control the current, you can't rely on the equivalent "resistance" (i.e. Vd/Id).

The premature failure of the LED bulb is caused exclusively by the embedded electronics degrading at high temperature. Since the LED is still dumping a lot of heat when working, the heat must be dissipated (hence puny LEDs and bulky, machined Al heatsinks) or the electronics get fried.

Guess what the drive to reduce the manufacturing cost will do to the quality of the LED bulbs?

I wonder how many slashdotters will get this reference...

the Idiocracy syndrome cuts both ways. Yeah, the official reaction was a little over the top. However, I pity the young lad for having no imagination whatsoever. Nothing in the wide world to write about but more gore in a school setting? Right.

The number 12 is involved only in the foot/inch ratio. Other stuff (lb/oz = 16, yd/ft=3, mi/yd=1760 - wtf!) is even whackier.

Although I agree that woodworking is much better in inches than in millimeters.

You're actually talking about today's Albania, isn't it? Wikipedia does mention that all fixed-wing aircraft have been retired from their Air Force in the last couple of years.

Q: Why did Albanian airforce not participate in WW2? A: The pilot was sick.

Sounds similar to SK's Space Program issue.

http://www.fieldbrook.net/TechTips/Humor/Bluetooth.asp

Repeat slowly after me: Elop, Stephen Elop. Elon Musk is a different (way different!) person...

Unfortunately, that's not true. The output is AC and the input-referred current will reflect it, i.e. will be quite high when the output reaches its highest (340V). Since the input source has an equivalent internal resistance of 10Ohm and would droop too much, some bulk capacitance is needed to provide these 120Hz current surges.

I agree with you that the design revolves around the placement of power components (capacitors, inductor, power switches and some sort of heatsinking), then the control circuitry be crammed in the spaces between them.

Having read the actual spec, I realized that my question was stupid. Input voltage is 450V, therefore the inverter is just a full-bridge DC/DC converter

The challenge is actually perfectly doable, with the only difficult points being the size of the switching inductor and the input bulk (most likely tantalum) and output filtering (must be ceramic) capacitors. IOW, the winner will be the one with the best connections to component manufacturers.

Having read the actual Spec Document, the input voltage is 450V DC, with an equivalent series resistance of 10Ohm. Definitely not 12V DC.

what is the state of the art w.r.t. the 12VDC->110VAC/60Hz 1kW inverters?

I stand corrected. Thanks for the link.

One thing I never understood is why so many posters on /. believe that Comp-Sci is the only highly technical field that matters. H1B visa holders are many times technically-educated people who have nothing to do with programming (i.e. Chemistry, Materials Physics, EE etc).

The Sun does not revolve around IT, so why are we suggesting it does?

I have half-bricks on the bottom of my gas-fired oven. It bakes much more evenly and keeps the temperature very steady.

Yes, thermal mass is the ticket, not just-in-time heat control gimmicks.